The present invention relates to apparatuses for physical exercise, and in particular combined exercisers and physical performance monitoring systems having the ability to provide a variety of different force loadings and rates of force loading.
Physical exercise, therapy and rehabilitation contain a wide variety of apparatus directed at various specific muscle groups and special purpose applications. Many of the exercise machines are directed solely to the objective of providing the user with a workout of certain muscle groups. This is typically done with the goal being to develop certain physical aspects, for example, leg muscles, arm muscles, or general cardiovascular stamina.
There has also been somewhat different development in the area more properly considered physical therapy and/or physical rehabilitation machines. Rather than merely emphasizing development of muscles and general overall physical endurance, these more specialized machines monitor the performance of the user. Such physical monitoring machines may also be programmed to provide a certain level of force or resistance to a user in an effort to achieve a desired effect on the user. For example, in U.S. Pat. No. 5,421,798, to Bond et al. describes a system which can be programmed to apply a predetermined load to the limb of a user of the apparatus. The apparatus of Bond is further provided with instrumentation to determine certain kinematics and kinetics of the user while using the apparatus.
Another example is provided in U.S. Pat. No. 5,401,224 Tsuchiya et al. which describes a method for measuring instantaneous leg power generated by the user of a physical therapy apparatus. Tsuchiya et al. provide for a display to communicate to the user the final measurement of the power generated by the user.
Despite these approaches there are a number of limitations in the art. One common limitation involves the relative inability of most physical therapy machines to apply a wide variety of different loads for use by different user""s having differing physical therapy or exercising needs. The need for flexibility in loading is also indicated in some exercise machines for increasing strength and durability, wherein it is desirable to provide a machine which allows for more resistance to be required as the user develops strength and is more easily able to overcome the initial resistance setting of the machine. In a rehabilitative setting, it is desirable to provide a machine which is able to decrease the resistance in areas where damage to tissue may occur through overuse, or to increase resistance in areas where muscles are used which need to be developed. Likewise, in a developmental setting, it is desirable to be able to provide an exercise machine having higher resistance in those areas where muscles are used which are desired to be developed. Most prior exercise machines have had difficulty in adapting to these needs and other desires imposed by physical therapists and users. Although common exercise machines have been able to achieve a variety of loads, these machines do not provide meaningful monitoring capabilities. These machines also provide loading which may be disadvantageous for many rehabilitative exercises, and thus cannot be used in this capacity.
Another problem experienced with prior art machines is the difficulty in achieving varying load rate changes during a stroke or other exercise cycle. Although we typically think in terms that a physical movement involves a certain force, it is more typical that forces vary significantly, due either to the type of machine being used or the particular position and anatomy involved. The human anatomy is such that depending upon the particular position of a body part, the load which can be reasonably worked by the muscle groups involved may vary considerably. For example, the leg is capable of producing very large forces when the leg is nearly extended. This should be contrasted to a position wherein the knee is fully bent, wherein relatively less force can be developed by the leg. The rate at which loading changes is different for different muscle groups and varies between individuals. Various exercises may not be therapeutically suitable due to a derogatory effect caused at one extreme of motion, position or loading. Most prior exercise and physical monitoring systems have had little success in providing a wide range of loads while also providing variable loading rates to be achieved.
Prior designs have used several methods to try to achieve different objectives in loading and loading rates. For example, U.S. Pat. No. 5,346,452 to Ku describes an exercise machine having pneumatic cylinders which are coupled to a servomotor which controls a relief valve controlling the amount of air which the pneumatic cylinder may exhaust in a given time period. By this means, the rate of exhaust and therefore the resistance imparted to the user may be varied by the servo. U.S. Pat. No. 4,235,437 to Ruis et al. describes an exercise machine having two hydraulic cylinders in a plane which allow for a variety of movements in the X-Y direction. By computer control of the hydraulic pressure within the cylinders, the machine can constrain the user interface to a predetermined path in the plane. The speed at which the user interface moves through the prescribed path may also be controlled by controlling the pressure in the hydraulic cylinders. The apparatus requires that a predetermined path and velocity be programmed into the computer prior to using the apparatus. This requirement greatly impedes use of the machine due to the complex setup requirements.
U.S. Pat. No. 5,312,315 to Mortensen et al. describes an exercise machine having a pneumatic cylinder which may be charged with an initial variable pneumatic gas pressure. In this way, the resistive force which must be overcome by the user may be elevated or lowered, thus elevating or lowering the resistive pressure over the full range of the stroke of the user interface. For example, doubling the initial pressure would also double the maximum force. This can result in an unacceptable force level. Such an approach does not provide flexibility to independently vary loading rates and the magnitude of the loading.
Another significant problem is the need to provide physical monitoring machines which provide accurate and reliable information over the full range of motion developed by the user. Improvements are needed with regard to understanding more completely, the actual forces, torques, velocities and accelerations developed by a user. Such information has not been sufficiently available for either therapy, training or physical diagnostic purposes.
Many prior exercise and physical therapy machines have also not adequately performed to users"" expectations because their construction and dynamic response capabilities may have a very noticeable effect on the users"" performance. For example, machines which utilize large weights or other large masses suffer from inertial effects which prevent effective training at high velocities while also providing development of large forces. Training for running sprints and many other high speed maneuvers have been particularly difficult given the technology which has existed to date. This difficulty coupled with poor diagnostic techniques have hampered athletes and physically impaired individuals who need an exercise apparatus with a high degree of mechanical compliance with the ability to vary forces. In many situations these individuals also need accurate information indicating the muscular performance which they are able to develop.
The prior art exercise machines either do not allow the resistive force to be varied, allow for the resistive force to be varied only in one dimension, e.g., such as elevating the resistive force over the entire range, or require complex microcomputer control systems to achieve the desired variation in movement of path and rate of movement of the user interface. It is therefore desirable to have an exercise/rehabilitative machine which can provide a variable resistive force throughout the extensive range of the user. It is also desirable to achieve this objective in a simple manner to reduce cost and complexity of the apparatus.
It is further desirable to provide an exercise apparatus with instrumentation and programmable control which allows the user""s performance to be calculated and immediately displayed to the user or to a therapist, thereby allowing immediate adjustments to be made and consequently the user""s performance to be enhanced.
Thus there is a strong need in the art for an exercise and physical performance monitoring system which can provide a high degree of flexibility and mechanical compliance to allow exercising at a wide variety of loads, loading rates, and velocities. There is also need for such a machine which can be easily adjusted. There is further a need for such a machine which can be used to collect and display data of value in assessing physical performance, physical performance limitations, injuries, and to indicate muscular strength and more general physical conditioning.